Small pinholes are apparent
If they're large and consistently in the same place, check the pad and cliche' for damage. Replace if necessary.
Colors transferring between pads on multi-color jobs.
In fast multicolor printing sequences a subsequent pad can remove a previous color.
This happens most often in larger print motifs on substrates not etched by the thinner. This usually occurs in connection with multi-station conveyors or turntables when using slow drying inks. This problem can be eliminated by initiating print and cliche' pauses.
Opacity of ink is poor
This is usually a direct result of printing on dark substrates with a single print. In these situations a second "hit" will usually bring the image up to a desired opacity level. Otherwise, a background print in white, or sometimes silver, will lay down a sufficient level of ink to make a brighter image.
Smudged image
This occurs when ink is too thin or pad slips during print. Slippage of pad during printing can be caused by too hard a pad, poor fixtures, angle of part in fixture, or excess pad pressure.
Image appears blotchy
A dry appearance or voids in the print is usually caused by ink which had dried in the image area of the cliche'.
Ink sticks to pad surface
If the pad picks up the image cleanly but does not drop-off entire image during print stroke, voids will appear in image.
Hairs on edges of image
This can be caused by a static charge in the part, but can also be due to other factors such as pad shape and improper ink viscosity.
Fine lines begin to close up
This problem usually occurs in reverse images where copy has dropped out of the artwork.
Solutions
Blurred or sharpness problem
Unsharp printing means blurred reproduction of lines or lettering.
Probable Cause
Possible Solution
Pad
Too soft.
Use a harder pad.
Wrong shape.
Use a different shape.
Clichè
Inaccurate etch.
make a new cliche'.
Etching is too deep.
Etch a new cliche' with less depth.
Wrong type of cliche'.
Use the suitable cliche' type(e.g. steel in place of polymer).
Wrong type of screen.
Test a new cliche' with a different screen.
Ink
Ink is too thick.
Add more thinner.
Ink is too thin.
Reduce the amount of thinner.
Slow drying.
Use a faster drying thinner or cliche' pause.
Material
Dirty surface.
Pre-clean.
Rough, grainy surface.
Switch over to other material, if possible, or try a harder pad.
Large differences in height.
Use special shaped pads and pad mounting devices.
Printing near edges.
Fixtures must support the pad to prevent slippage.
Other
Work piece fixtures are not stable enough.High speed causes pad vibration.
Make new fixtures.Decrease speed. If necessary, pause at front position before releasing the ink film to avoid vibrations of the pad during printing.
Ink does not meet adhesion requirements
This problem frequently occurs because the material of the product is unknown or the wrong type of ink is used.
Probable Cause
Possible Solution
Pad
Too much silicone on surface.
Clean new pads with alcohol beforeuse.
Clichè
Etched too deep.
Remake cliche' deeper.
Ink
Wrong type of ink.
Use the suitable ink according to thetechnical data sheet.
Bi-Component?
Use bi-component ink with hardener.
Incorrect ratio of ink to hardener.
Remix ink with correct ratio by weighing ink and hardener.
Material
Dirty surface.
Preclean with alcohol.
Other
No/insufficient pretreatment.
Check pretreatment procedure. If necessary, repeat.
Required cure time is not met.
Leave parts for longer period of time before testing.
No/insufficient after-treatment.
Use heat tunnel and in some situations flame parts.
Colors transferring between pads on multi-color jobs.
In fast multicolor printing sequences a subsequent pad can remove a previous color.
This happens most often in larger print motifs on substrates not etched by the thinner. This usually occurs in connection with multi-station conveyors or turntables when using slow drying inks. This problem can be eliminated by initiating print and cliche' pauses.
Probable Cause
Possible Solution
Pad
Porous, worn surface.
Replace pad.
Clichè
Etching is too deep.
Etch a new cliche' with less depth.
Wrong percentage and LPI of screen.
Test a new cliche' with a different screen. (higher DPI screen for smaller areas & detail)
Ink
Ink has too much thinner.
Add more pure ink to cup or inkwell.
Ink is drying too slow.
Use a faster drying thinner, blow air, or use pad delays/ pauses to give inks time to dry.
Material
Very smooth surface. Substrates which cannot be etched by the thinner (e.g., glass) are especially problematic.
Use hot/cool air blown onto part between colors, or use pauses before printing.
Opacity of ink is poor
This is usually a direct result of printing on dark substrates with a single print. In these situations a second "hit" will usually bring the image up to a desired opacity level. Otherwise, a background print in white, or sometimes silver, will lay down a sufficient level of ink to make a brighter image.
Probable Cause
Possible Solution
Pad
Porous and rough.
Replace pad.
Too flat and soft causing insufficient inkrelease.
Use a firmermore pointed pad.
Clichè
Etching depth is too low.
Etch a deeper cliche'.
Wrong type of screen.
Test a new cliche' with a different screen.
Wrong type of cliche'.
Use a different type of cliche'.
Ink
Ink too thin.
Thicken ink.
Ink not transferring completely.
Use print pause or air blower to partially dryink for proper release.
Material
Image not brilliant enough due to darkness of parts.
Smudged image
This occurs when ink is too thin or pad slips during print. Slippage of pad during printing can be caused by too hard a pad, poor fixtures, angle of part in fixture, or excess pad pressure.
Probable Cause
Possible Solution
Pad
Too hard.
Use a softer pad.
Too small in relation to the image.
Use a larger pad.
Prints over edges.
Adjust the pad stroke and/or use fixture with more support.
Clichè
Depth too deep.
Make a new cliche'.
Wrong type of cliche', may need screen.
Test a new cliche' with a screen or use a different type of screen.
Hairs on edges of image
This can be caused by a static charge in the part, but can also be due to other factors such as pad shape and improper ink viscosity.
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